New hope for people with rare kidney diseases

An EU-funded project has provided new hope for the 2 million people in Europe who suffer from rare kidney diseases thanks to groundbreaking research that has led to diagnostic tests and a new type of treatment.

New hope for people with rare kidney diseases

An EU-funded project has provided new hope for the 2 million people in Europe who suffer from rare kidney diseases thanks to groundbreaking research that has led to diagnostic tests and a new type of treatment.

Nephrotic syndrome (NS) is a rare condition where the kidneys become leaky and large amounts of protein seep from the blood into the urine, causing swelling, weight gain and tiredness. Patients with the inherited, or congenital, type of disease may need dialysis and kidney transplants, sometimes even in childhood, and may have a lower life expectancy.

Up to now, the greatest challenge to providing better care for people suffering from this and other rare kidney diseases has been that researchers have not been able to obtain a critical mass of bio samples from patients for analysis.

The EU-funded EURENOMICS project sought to tackle this problem by collecting DNA, blood and urine from a large number of patients and evaluating these using novel high-throughput technologies.

While it is known that there are 35 genes that cause nephrotic syndrome, the underlying causes of many other rare kidney diseases are not known. Even where knowledge exists, it has not been translated into clinical practice.

Through EURENOMICS, novel technologies in gene and biomarker testing have helped patients benefit directly from research progress.

Where genetic testing was previously done it was very slow and tedious but with next generation sequencing technology we have been able to get results for up to 35 genes within a few days, says EURENOMICS project coordinator Franz Schaefer, head of paediatric nephrology at the University of Heidelberg in Germany.

Schaefer said identifying the genetic basis of kidney disease was important as doctors could use it to practise personalised medicine and predict which treatments, such as chemotherapy drugs, would work for individuals and what the prognosis is for progression of the disease.

New tests and treatments

EURENOMICS brought together around 100 of the best kidney clinicians and researchers in Europe from a total of 10 countries.

The five-year consortium developed a number of diagnostic tests, including four kits that will be made available commercially to cover a range of genetic kidney diseases.

This will make the whole process of screening for kidney diseases quicker and more efficient, says Schaefer. It will also make it easier to predict how fast the disease will progress.

The kits were developed by taking urine samples from patients with kidney disease and screening them for abnormal proteins.

The team also managed to identify a group of genes that were amenable to pharmacological treatments. One type in particular, which causes a mitochondrial disorder, responded to the simple drug coenzyme Q10. (Mitochondria generate energy for cells.) This is effectively a cure for 10 % of patients who have genetic nephrotic syndrome, says Schaefer.

For most of the other genetic types we don't have a treatment yet  but we're working on it, he adds.

Prenatal screening

The scientists developed cell culture models and tested existing drug compounds on them to see if these had any effects and could be repurposed to treat rare kidney diseases. Already established as safe and with known side effect profiles, these drugs would be quick to bring to market, with the process far less costly compared to developing new ones.

Another discovery was the development of an amniotic fluid screening test, which may be able to be used in prenatal screening to accurately predict future moderate to severe kidney disease in babies.
EURENOMICS also has a biobank of DNA-containing samples from 20 000 patients that will be used in ongoing research.

Overall the project has surpassed all our expectations, says Schaefer. Our group has published 300 papers, developed four new diagnostic tests which will be available commercially and a new treatment for 10 % of genetic nephrotic syndromes. We have greatly advanced the understanding of the causes of rare kidney diseases.